title: Usefulness of biochemical parameters in decision-making  on the start of emergency treatment in patients  with propionic acidemia.
abstract: BACKGROUND
  Recurrent acute and life-threatening metabolic decompensations are thought to be the major cause of mortality and morbidity in patients with propionic acidemia (PA). Since metabolic decompensations in these patients usually develop gradually, there is considerable uncertainty about the beginning and when emergency treatment should be initiated. The major aim of this study was to evaluate the usefulness of biochemical parameters for improving decision-making on the start of emergency treatment.
  
  
  METHODS
  We analysed data of 16 PA patients continuously followed in our centre. Metabolic decompensation was defined clinically by the occurrence of at least one of three alarming symptoms: vomiting, food refusal or impaired consciousness. Thirty-eight biochemical parameters were analysed.
  
  
  RESULTS
  A total of 259 metabolic decompensations were documented and compared with 625 routine visits. Among the symptoms used to clinically define metabolic decompensations, vomiting was most frequent (87 %). In total, 19 biochemical parameters differentiated between metabolic decompensations and routine visits. Among them ammonia, acid-base balance and anion gap were most reliable to identify a metabolic decompensation, and to estimate its severity. A comparative analysis of patients with PA and methylmalonic acidemia during metabolic decompensation showed similar results.
  
  
  CONCLUSIONS
  Ammonia, acid-base balance and anion gap are important biochemical parameters to identify an (impending) metabolic decompensation and to assess its severity in PA patients. The identified biochemical parameters should be integrated in an algorithm for clinical decision-making on emergency treatment and should be tested in a prospective trial.
authors.forename: Tamaris
authors.initials: T
authors.lastname: Zwickler
authors.forename: Alina
authors.initials: A
authors.lastname: Riderer
authors.forename: Gisela
authors.initials: G
authors.lastname: Haege
authors.forename: Georg F
authors.initials: GF
authors.lastname: Hoffmann
authors.forename: Stefan
authors.initials: S
authors.lastname: Kölker
authors.forename: Peter
authors.initials: P
authors.lastname: Burgard
mesh_terms: D000136:Acid-Base Equilibrium; D000293:Adolescent; D000328:Adult; D000592:Amino Acid Metabolism, Inborn Errors / Q000097:blood; D000641:Ammonia / Q000737:chemistry; D001066:Appetite; D002648:Child; D002675:Child, Preschool; D003657:Decision Making; D003661:Decision Support Techniques; D004638:Emergency Treatment; D006801:Humans; D011422:Propionates / Q000737:chemistry; D056693:Propionic Acidemia / Q000097:blood* / Q000175:diagnosis / Q000628:therapy*; D014474:Unconsciousness; D014839:Vomiting; D055815:Young Adult
chemical_list: D011422:Propionates; D000641:Ammonia